Shorthand to test if an object exists in an array for Swift?

Question

Currently, I have an array of objects like this:

var myArr = [   MyObject(name: "Abc", description: "Lorem ipsum 1."),   MyObject(name: "Def", description: "Lorem ipsum 2."),   MyObject(name: "Xyz", description: "Lorem ipsum 3.") ] 

I am testing if an object exists before proceeding like this:

let item = myArr.filter { $0.name == "Def" }.first if item != nil {   // Do something... } 

But I'm looking for a shorter way to do this since I am doing this a lot. I'd like to do something like this but it is invalid:

if myArr.contains { $0.name == "Def" } {   // Do something... } 

Is there any shorthand syntax I'm missing or a better way to do this?

Answer 1

Why not use the built-in contains() function? It comes in two flavors

func contains<S : SequenceType, L : BooleanType>(seq: S, predicate: @noescape (S.Generator.Element) -> L) -> Bool func contains<S : SequenceType where S.Generator.Element : Equatable>(seq: S, x: S.Generator.Element) -> Bool 

and the first one takes a predicate as argument.

if contains(myArr, { $0.name == "Def" }) {     println("yes") } 

Update: As of Swift 2, both global contains() functions have been replaced by protocol extension methods:

extension SequenceType where Generator.Element : Equatable {     func contains(element: Self.Generator.Element) -> Bool }  extension SequenceType {     func contains(@noescape predicate: (Self.Generator.Element) -> Bool) -> Bool } 

and the first (predicate-based) one is used as:

if myArr.contains( { $0.name == "Def" }) {     print("yes") } 

Swift 3:

if myArr.contains(where: { $0.name == "Def" }) {     print("yes") } 

Answer 2

IMHO to achieve the desired behavior you would have to create an extension class to the array that would look something like:

extension Array {     func contains(test: (T) -> Bool, action: (T) -> Void) {         let filtered = self.filter(test)         if(filtered.is​Empty) {             action(filtered)         }     } } 

I don't have xcode in front of me so I apologize if i have a syntax error. However if you are using the often you can write it as follows

myArr.contains({ $0.name == "Def"}) {    // Do something... } 

I would rename it as to prevent confusion in your code.